873b477177
Sometimes, application responses become bad under heavy memory load. Applications take a bit time to reclaim memory. The statistics, how long memory reclaim takes, will be useful to measure memory usage. This patch adds accounting memory reclaim to per-task-delay-accounting for accounting the time of do_try_to_free_pages(). <i.e> - When System is under low memory load, memory reclaim may not occur. $ free total used free shared buffers cached Mem: 8197800 1577300 6620500 0 4808 1516724 -/+ buffers/cache: 55768 8142032 Swap: 16386292 0 16386292 $ vmstat 1 procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu---- r b swpd free buff cache si so bi bo in cs us sy id wa 0 0 0 5069748 10612 3014060 0 0 0 0 3 26 0 0 100 0 0 0 0 5069748 10612 3014060 0 0 0 0 4 22 0 0 100 0 0 0 0 5069748 10612 3014060 0 0 0 0 3 18 0 0 100 0 Measure the time of tar command. $ ls -s test.dat 1501472 test.dat $ time tar cvf test.tar test.dat real 0m13.388s user 0m0.116s sys 0m5.304s $ ./delayget -d -p <pid> CPU count real total virtual total delay total 428 5528345500 5477116080 62749891 IO count delay total 338 8078977189 SWAP count delay total 0 0 RECLAIM count delay total 0 0 - When system is under heavy memory load memory reclaim may occur. $ vmstat 1 procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu---- r b swpd free buff cache si so bi bo in cs us sy id wa 0 0 7159032 49724 1812 3012 0 0 0 0 3 24 0 0 100 0 0 0 7159032 49724 1812 3012 0 0 0 0 4 24 0 0 100 0 0 0 7159032 49848 1812 3012 0 0 0 0 3 22 0 0 100 0 In this case, one process uses more 8G memory by execution of malloc() and memset(). $ time tar cvf test.tar test.dat real 1m38.563s <- increased by 85 sec user 0m0.140s sys 0m7.060s $ ./delayget -d -p <pid> CPU count real total virtual total delay total 9021 7140446250 7315277975 923201824 IO count delay total 8965 90466349669 SWAP count delay total 3 21036367 RECLAIM count delay total 740 61011951153 In the later case, the value of RECLAIM is increasing. So, taskstats can show how much memory reclaim influences TAT. Signed-off-by: Keika Kobayashi <kobayashi.kk@ncos.nec.co.jp> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujistu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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.. | ||
allocpercpu.c | ||
backing-dev.c | ||
bootmem.c | ||
bounce.c | ||
dmapool.c | ||
fadvise.c | ||
filemap.c | ||
filemap_xip.c | ||
fremap.c | ||
highmem.c | ||
hugetlb.c | ||
internal.h | ||
Kconfig | ||
maccess.c | ||
madvise.c | ||
Makefile | ||
memcontrol.c | ||
memory.c | ||
memory_hotplug.c | ||
mempolicy.c | ||
mempool.c | ||
migrate.c | ||
mincore.c | ||
mlock.c | ||
mm_init.c | ||
mmap.c | ||
mmzone.c | ||
mprotect.c | ||
mremap.c | ||
msync.c | ||
nommu.c | ||
oom_kill.c | ||
page-writeback.c | ||
page_alloc.c | ||
page_io.c | ||
page_isolation.c | ||
pagewalk.c | ||
pdflush.c | ||
prio_tree.c | ||
quicklist.c | ||
readahead.c | ||
rmap.c | ||
shmem.c | ||
shmem_acl.c | ||
slab.c | ||
slob.c | ||
slub.c | ||
sparse-vmemmap.c | ||
sparse.c | ||
swap.c | ||
swap_state.c | ||
swapfile.c | ||
thrash.c | ||
tiny-shmem.c | ||
truncate.c | ||
util.c | ||
vmalloc.c | ||
vmscan.c | ||
vmstat.c |